PRAGUE, Oct 23 (Reuters) The United States has proposed keeping parts of its missile defence shield on ''stand-by'' short of full readiness in a bid to soothe Russian concerns, US officials and NATO envoys said today.
Under the proposal, the shield would be fully activated only when a threat emerged. Key to any progress on the idea would be Moscow and Washington overcoming divergences over the imminence of the threat from a state such as Iran, officials said.
''The difference is over timelines, how soon the ballistic missiles with a range that could reach the United States or greater parts of Europe can be achieved,'' a senior US government official told Reuters.
''The Russians say later rather than sooner. We say sooner rather than later,'' said the official, who was speaking on condition of anonymity, of estimates on the state of Tehran's missile programmes.
The United States plans to place interceptor missiles in Poland and a radar system in the Czech Republic as part of a shield Washington says is needed to counter possible attacks from ''rogue states'' including Iran and North Korea.
President Vladimir Putin mentioned last week US efforts to address concerns over a system which Moscow believes could target Russia, but did not refer to specific initiatives.
US Pentagon chief Robert Gates and US Secretary of State Condoleezza Rice brought proposals to Moscow earlier this month, but public attention focused on a separate move to allow Russian authorities to inspect the shield installations.
''The Russians were surprised and need time to think about it,'' said one NATO diplomat of the proposal to keep parts of the shield on stand-by.
FULLY OPERATIONAL Under the proposal, the system would be built to be fully operational but kept in a stand-by mode pending development of any threat.
The US official described the initiative as one of a number of ''high-concept proposals'' being left deliberately vague for now because of uncertainty over the Russian response.
''There are a variety of different steps, half-steps, half-measures that could be, might be, implemented if we actually are able to reach agreement with the Russians on the threat with Iran,'' the official said.
''So any idea of, you know, not activating the system -- any firm notion that we won't activate the system till we get Russian compliance isn't something that is so explicit.'' The West suspects Tehran of seeking the atom bomb and rejects its arguments that its nuclear programme is intended purely for generating electricity.
Gates is due to meet his Russian counterpart Anatoly Serdyukov at a meeting of NATO defence ministers on the Dutch coast on Wednesday and Thursday. Russia is routinely invited to such talks to try to further NATO-Russia cooperation.
The missile shield dispute has been one of several at the heart of a chilling of relations between Moscow and the West over the past year. Russia has said it may spark a new arms race and Putin has said he could re-deploy some of Russia's weapons if its concerns were not heeded.
REUTERS SZ KP1735